In displays of laptop computers, liquid-crystal monitors and the like, antiglare properties are realized usually by applying a mixture of organic or inorganic particulates and a binder resin or a curable resin on a base material and forming irregularity on the surface in order to prevent reflection of the outside scenery on the display surface. In order to improve the antiglare properties, the shape of the irregularity needs to be enlarged or the frequency of the irregularity needs to be increased. However, if the irregularity is large or the frequency thereof is increased, the haze value (haze degree) of the antiglare layer is raised, and though the antiglare properties are obtained, there are problems of white blur on the screen caused by reflection of external light and lowered image clarity caused by the rise in the haze value, which deteriorates visibility of a display image. Moreover, if the haze value on the surface, which is a general evaluation of the prior-art antiglare hard coat film, is lowered, though the degree of white blur of the screen caused by reflection of the external light can be suppressed, glaring brightness referred to as so-called scintillation (glare) becomes strong on the film surface. In order to solve this, a method of raising the haze value inside the antiglare layer has been used, but light transmittance is lowered by internal haze caused by a refractive index difference between the particulates and the resin, which lowers display brightness of the display device, and since a coated film becomes whitish due to the internal haze at the same time, contrast deterioration is extreme.
For example, Japanese Unexamined Patent Application Publication No. 11-326608 (Patent Document 1) discloses an antiglare film in which translucent particulates having an average grain size of 0.5 to 5 μm and a difference in refractive index from the light transmissive resin is 0.02 to 0.2 are mixed. Patent Document 1 describes that by setting the difference in refractive index between the translucent resin which forms the antiglare layer and the translucent particulates contained therein to 0.02 to 0.2, image clarity can be improved without lowering diffusion/antiglare properties and in this case, even if the haze value is raised so as to reduce glaring, the image clarity can be maintained high. However, antiglare properties are ensured with the specifically obtained haze of the film as high as 10% or more, while the coated film becomes whitish, and deterioration in the light transmittance and contrast are extreme.
Also, with Japanese Unexamined Patent Application Publication No. 2008-286878 (Patent Document 2), since the refractive index difference between a hardened substance in a binder and translucent particulates is kept to a small range of 0 to 0.05 in the antiglare film, light transmittance inside the antiglare hard coat layer can be improved, and since arithmetic average roughness (Ra) measured in compliance with JIS B 0601-1994 is 0.01 to 0.30 μm and an average interval (Sm) of irregularity is kept to a small range of 10 to 300 μm on the surface of the antiglare hard coat layer, light diffusion on the surface (outer face) of the antiglare hard coat layer is exerted, while light transmittance can be maintained, and with the antiglare film, suppression of glaring and improvement of transmissive clarity can be exerted in a well-balanced manner. However, the ranges of the arithmetic average roughness (Ra) at 0.01 to 0.30 μm and the average interval (Sm) of irregularity at 10 to 300 μm are not small, and most of the antiglare films merchandized in the market at present fall into this range. Also, with the specifically obtained film having the arithmetic average roughness (Ra) at 0.1 μm or more, a value of image clarity measured through an optical comb having a width at 2 mm at less than 70%, and the value of the image clarity measured by reflection at 60% or less, the antiglare properties are ensured, but there remains problems that prevention of glare on a high-definition panel is insufficient, whitishness of the coated film is not considered and deterioration in the light transmittance and contrast are extreme.